“I think he has done really a great job of outsmarting our country,” Donald Trump told Larry King in 2013.

He was referring to Russian President Vladimir Putin and his policy in Syria.

Long before he became president, Trump saw the pitfalls of U.S. policy toward Syria that entrapped the Obama administration. But now, even under the Trump administration, Moscow continues to “outsmart” Washington by ignoring the deconfliction arrangement when it suits its interests.

“Deconfliction” is an informal agreement reached in 2015 between U.S.-led coalition forces and Russian military forces in Syria to avoid clashes.

But as the Islamic State, also known as ISIS, “caliphate” has been whittled away, Russian, Syrian, Iranian, and Hezbollah forces have begun operating in closer proximity to U.S.-backed Syrian rebel groups on the ground, and have frequently attacked them.

This constitutes a breach of the 2015 agreement—though it should have been expected, as the agreement is nonbinding.

In response, U.S. military leaders have reminded their Russian counterparts about the locations of coalition forces and their Syrian rebel partners, and tried to calm tensions.

In other words, Russia has suffered no consequences for its harmful behavior.

Moscow and Washington have conflicting goals in Syria. Russia seeks to prop up the Assad regime, which has granted it expanded access to air and naval bases in western Syria.

The United States, on the other hand, has called for Syrian President Bashar Assad to leave power as part of a negotiated transition to a new government that could end Syria’s six-year-long civil war.

The top U.S. priority in Syria is to defeat ISIS. But Russia is not a useful ally against ISIS. To the contrary, it seeks to undermine U.S. interests in the region.

While Russia claims to be in Syria to support the fight against ISIS, more Russian airstrikes hit moderate rebel groups than ISIS positions this past spring. Russia’s direct targeting of anti-Assad rebel groups underscores the fact that Russia backs Assad’s stated goal of reclaiming all Syrian land from “terrorists,” whom Assad defines as any group that resists his brutal dictatorship.

It should also be noted that undermining agreements over Syria is nothing new for Moscow.

The Obama administration fell victim to Russian duplicity when a “cessation of hostilities” was brokered between Secretary of State John Kerry and his Russian counterpart Sergey Lavrov.

Nonetheless, the fighting did not completely halt. Instead, the Russian-Syrian-Iranian coalition used the agreement as a means of consolidating its control over territory and tightening its grip on Aleppo, a key rebel stronghold that was pulverized in an indiscriminate bombardment by Assad’s army.

Additionally, the Obama administration agreed to another dubious deal with Moscow in 2013 to peacefully destroy Assad’s chemical weapon arsenal by mid-2014. But Syria not only failed to destroy all of its chemical weapons, it continued to use them against the rebels.

This past April, the Assad regime launched another chemical weapon attack, which provoked the Trump administration to launch a cruise missile strike against the air base that had launched the attack.

Despite Syria’s continued use of chemical weapons, Russia recently vetoed a United Nations Security Council resolution to extend the mandate of the only official investigation into chemical attacks in Syria.

The Trump administration, which entered office with hopes of working with Russia to fight ISIS in Syria, should be careful to avoid falling victim to the same empty Russian promises that deceived the previous administration.

Skepticism over the value of the deconfliction agreement proved to be warranted when Russia supported an offensive by Syrian and Iranian-led forces. That offensive crossed the Euphrates River, which was supposed to be the boundary between Russia’s allies and the Syrian Democratic Forces, a U.S.-supported rebel coalition.

Both sides are now racing to take control of key Syrian oil and gas fields, but recent reports claim that at least one major oil field is under the control of the Syrian Democratic Forces.

The competition to gain control over key oil and gas fields after the defeat of ISIS will be a critical factor in determining the future of Syria.

Thus far, the Trump administration has narrowly focused on defeating ISIS and said little about its post-ISIS plans.

While the defeat of the terrorist threat in Syria should be the highest immediate priority, the administration needs to keep in mind that ISIS terrorism is only a piece of the Syrian and Middle Eastern puzzle.

Iran is a bigger long-term threat than ISIS and the U.S. will need reliable allies on the ground to roll back Iranian influence in Syria and prevent Tehran from consolidating a land bridge across Iraq and Syria to Lebanon.

To shore up regional stability and protect U.S. interests and allies, Washington must remain engaged in Syria. If the U.S. merely walks away from Syria after the defeat of ISIS, it will enable Russia and Iran to consolidate their dominance in that key country and further undermine the U.S. and its allies in the region

The administration needs to look at the region as a whole rather than solely focusing on the defeat of ISIS. While Russia and Iran may also seek to destroy ISIS, both nations are part of the larger problem that threatens U.S. interests in the Middle East.

For more on this topic:

After Missile Strike in Syria, Trump Must Avoid Mission Creep

Assad Is Using Chemical Weapons. How Trump Can Counter the Barbarism.

How President Trump Can Improve US Syria Policy

Obama Administration Once Again Concedes to Putin in Syria

Time for the Obama Administration to Respond to Syrian Chemical Attacks

Obama’s Ad Lib Syria Policy Puts Putin in Driver’s Seat